The use of intrabody medical equipment, such as endoscopes, catheters, and the like, for surgical, diagnostic and therapeutic purposes is rapidly expanding. To improve performance, the equipment has been optimized to best accomplish selected purposes. For example, endoscopes have been optimized and refined to provide upper endoscopes for examination of the esophagus, stomach, and duodenum; colonoscopes for the colon; angioscopes for blood vessels; bronchoscopes for the bronchi; laparoscopes for the peritoneal cavity; arthroscopes for joint spaces; nasopharygoscopes for nasal passages and the pharynx; and intubation scopes for a person's airway.
A conventional endoscope 11, shown in FIG. 1, has an insertion tube 12 that is connected at a proximal end 14 to a handle or headpiece 16. The insertion tube 12 is adapted to be inserted into a patient's body to perform a selected surgical, therapeutic or diagnostic procedure. The endoscope 11 is generally manufactured with either a rigid or flexible insertion tube 12. The rigid insertion tube 12 maintains its shape to allow the operator to change the position of the portion of the insertion tube 12 that is within the body by applying torque to the portion of the endoscope 11 that is outside the body. The flexible insertion tube 12, on the other hand, cannot be controlled in such a manner. Instead, control wheels 24 are mounted on the headpiece 16 and connected to the insertion tube's distal end 20 by control cables (not shown). The control wheels 24 are manipulated to bend the insertion tube's distal end 20 to move the distal end 20 up, down, left, or right. Accordingly, the distal end 20 can be controlled to allow improved visibility or positioning of working tools within the patient's body.
The insertion tube 12 often contains an imaging system 18 having optical fibers or the like extending along the length of the insertion tube and terminating at a viewing window 19 in the insertion tube's distal end 20. The imaging system 18 conveys an image from a viewing window 19 to an eyepiece 22 on the headpiece 16, or to a monitor (not shown), so that the user can see into a selected body cavity during an endoscopic procedure. Through manipulation of the control wheels 24, an operator can cause the distal end 20 of the insertion tube 12 to become substantially linear, or to take a curved shape (two possible curves being illustrated in FIG. 1) to selectively position the viewing window 19. The endoscope 11 is described in greater detail in U.S. Pat. No. Re 34,110 and U.S. Pat. No. 4,646,722, which are incorporated by reference.
Different endoscopic procedures are best performed with endoscopes having insertion tubes with particular bending characteristics. For example, laparoscopy is typically performed with an endoscope having a rigid or semi-rigid insertion tube. Endoscopic intubation is also performed with a rigid endoscope so as to allow for positioning with leverage during insertion into the body. Other endoscopic procedures use endoscopes with flexible insertion tubes, such as colonoscopes, bronchoscopes and arthroscopes. Thus, facilities need several different endoscopes. The endoscopes, however, are not suitably interchangeable between procedures. Endoscopes can be expensive and, as a result, owning large numbers of them is often cost prohibitive.
While endoscopes provide an excellent way to perform selected, minimally invasive surgeries in a time and cost effective manner, some endoscopes have limited versatility for performing a range of endoscopic procedures. Endoscopes with rigid insertion tubes have limited versatility because the insertion tube's distal end cannot be steered around corners. Accordingly, the rigid endoscopes may not be able to access or view particular areas in a body cavity. In certain of these situations, endoscopes with flexible or semi-rigid insertion tubes could work well. Flexible insertion tubes, however, have other limitations which are described below.
Rigid endoscopes are typically made from metal, such as stainless steel, and therefore could be sterilized in an autoclave prior to surgery. Endoscopes having flexible insertion tubes, on the other hand, typically have a flexible outer coating, such as a rubberized material, and, as a result, could not be safely autoclaved. As a result, flexible endoscopes are usually more difficult to thoroughly sterilize. Thus, for sterility reasons, minimally invasive surgery was traditionally performed most often with endoscopes having rigid insertion tubes.
To solve some of these problems, protective endoscopic sheaths have been developed to protect insertion tubes from the contaminated external environment, and to protect patients from contaminated insertion tubes. U.S. Pat. No. 4,646,722 to Silverstein et al., for example, shows a flexible sheath for surrounding the flexible insertion tube of the endoscope. A protective, flexible sheath that is both sterile and disposable can be placed over either a rigid or flexible insertion tube to prevent the insertion tube from being contaminated. After use, the sheath can be discarded. The endoscope can be prepared for the next procedure by merely replacing the sheath with a new, sterile sheath, thereby considerably reducing preparation and down time of the endoscope between procedures.
There is a need for an endoscope system that achieves the benefits of an endoscope with rigid insertion tubes as well as the benefits of an endoscope with a flexible insertion tube. There is also a need for an endoscope system that overcomes the limited versatility of endoscopes having rigid insertion tubes and the sterilization difficulties experienced by endoscopes having flexible insertion tubes. Accordingly, there is a need for an endoscope system that allows one endoscope to be used effectively and efficiently for a range of procedures which typically require insertion tubes with different bending characteristics.